@ Ben - Yes, that's what I mean about getting the communication right. God only knows how bad it could be at peak times and I think the authorities need to get their act together in this regard.
@ Hom3r - I heard that they were talking about cutting a gap in the central reservation but only after many hours and don't know if they actually did in the end. IIRC the other side of the motorway was also closed and if so there'd be no reason not to allow vehicles to do a U turn and head back the other way would there?
It's really not difficult to imagine the sort of chaos which could very easily be created by anyone with a desire to do so. A few dodgy packages dumped strategically on the hard shoulder of a some busy motorways and there's going to be protracted gridlock affecting thousands of motorists and vehicles/ambulances carrying potentially important or even vital goods, equipment, people etc.
The official response to these events may be being done by the book but IMHO the book needs a serious review to take account of the reality that it's all much too slow and cumbersome for the world we live in. I'd love to hear from anyone with any inside knowledge of how these incidents are handled and whether or not anything is under review.